Research Report Psychological Science XX(X) 1 –7 The Neurogenetics of Nice: Receptor Genes © The Author(s) 2012 Reprints and permission: sagepub.com/journalsPermissions.nav for Oxytocin and Vasopressin Interact With DOI: 10.1177/0956797611428471 Threat to Predict Prosocial Behavior http://pss.sagepub.com Michael J. Poulin1, E. Alison Holman2, and Anneke Buffone1 1Department of Psychology, University at Buffalo, and 2Department of Nursing Science, University of California, Irvine Abstract Oxytocin, vasopressin, and their receptor genes influence prosocial behavior in the laboratory and in the context of close relationships. These peptides may also promote social engagement following threat. However, the scope of their prosocial effects is unknown. We examined oxytocin receptor (OXTR) polymorphism rs53576, as well as vasopressin receptor 1a (AVPR1a) polymorphisms rs1 and rs3 in a national sample of U.S. residents (n = 348). These polymorphisms interacted with perceived threat to predict engagement in volunteer work or charitable activities and commitment to civic duty. Specifically, greater perceived threat predicted engagement in fewer charitable activities for individuals with A/A and A/G genotypes of OXTR rs53576, but not for G/G individuals. Similarly, greater perceived threat predicted lower commitment to civic duty for individuals with one or two short alleles for AVPR1a rs1, but not for individuals with only long alleles. Oxytocin, vasopressin, and their receptor genes may significantly influence prosocial behavior and may lie at the core of the caregiving behavioral system. Keywords oxytocin, vasopressin, genetics, prosocial behavior, threat, ideology, social behavior, stress reactions Received 4/28/11; Revision accepted 10/5/11 The highly similar peptides oxytocin and vasopressin have such threats, they may influence a wide variety of prosocial emerged in the literature as promising candidates for the behaviors, including those outside a laboratory context. biological underpinnings of prosociality (for reviews, see Campbell, 2010; Ebstein et al., 2009). Research on oxytocin administration and on variation in the oxytocin receptor gene Oxytocin, Vasopressin, and Threat (OXTR) has suggested that oxytocin influences generosity in the Moderation context of economic games, as well as empathy, prosocial tem- Evidence suggests that oxytocin moderates responses to some perament (e.g., Bartz et al., 2010; Israel et al., 2008; Kosfeld, threats (for a review, see Campbell, 2010). Oxytocin adminis- Heinrichs, Zak, Fischbacher, & Fehr, 2005; Mikolajczak et al., tration reduces amygdalar reactivity to negative stimuli 2010; Tost et al., 2010), and interactions with close others (Kirsch et al., 2005; Petrovic, Kalisch, Singer, & Dolan, 2008), (Bakermans-Kranenburg & van IJzendoorn, 2008; Ditzen et al., and amygdalar reactivity, in turn, mediates oxytocin’s effects on 2008; Feldman, Gordon, Schneiderman, Weisman, & Zagoory- generosity in the context of an economic game (Baumgartner, Sharon, 2010). Similarly, research on variation in the vasopres- Heinrichs, Vonlanthen, Fischbacher, & Fehr, 2008). The G/G sin 1a receptor gene (AVPR1a) has indicated that vasopressin genotype of the rs53576 single-nucleotide polymorphism influences generosity and endorsement of benevolent values in (SNP) for OXTR also predicts lower cardiovascular reactivity the context of economic games (Knafo et al., 2008), as well as to startle anticipation than do the A/A and A/G genotypes pair bonding in men (Walum et al., 2008). (Rodrigues, Saslow, Garcia, John, & Keltner, 2009). The psychological mechanisms for the effects of oxytocin Vasopressin also appears to moderate responses to certain and vasopressin on prosociality and the scope of these hor- threats. In nonhuman animals, vasopressin administration mones’ influence on prosocial behaviors outside the contexts of the laboratory and close relationships remain unknown. Corresponding Author: However, all prosocial acts require people to contend with Michael J. Poulin, Department of Psychology, University at Buffalo, Park Hall concerns about potential exploitation or loss of resources (i.e., 206, Buffalo, NY 14260 threats). If oxytocin and vasopressin moderate responses to E-mail: [email protected] 2 Poulin et al. leads to increased behavioral displays of fear, but vasopressin recruited by Knowledge Networks (http://www.knowledgenet deficiency is also associated with increased fear (see Jones & works.com). Knowledge Networks panel members are compen- Gosling, 2008, for a review). In both humans and nonhuman sated with Internet access (if needed), points that can be used animals, vasopressin administration increases not only physi- toward purchasing merchandise, and monetary rewards in ological arousal (Ebstein et al., 2009; Shalev et al., 2011) but return for completing certain surveys. Data used for this investi- also approach-oriented emotions in response to potentially gation were collected at several time points, described in the threatening faces (Thompson, George, Walton, Orr, & Benson, following paragraphs. Because genotype distributions differ 2006). Notably, variation in the rs1 and rs3 AVPR1a polymor- across racial groups, our analyses focused on European Ameri- phisms moderates amygdala activity in response to emotional cans, who composed the largest racial group in the sample. For faces (Meyer-Lindenberg et al., 2008), as well as the startle the present study, 518 European American participants (48.8% response (Levin et al., 2009). male, 51.2% female) were successfully genotyped for one or more polymorphisms of interest. Of these participants, 348 had participated in data collection at all time points and were The Present Study: OXTR, AVPR1a, and included in our analyses. Real-World Prosocial Behavior Our goal in this study was to examine whether oxytocin and Life-event surveys. All individuals in this study participated vasopressin interact with threat to predict prosocial behavior in a survey-based study on responses to life events (N = outside the contexts of the laboratory and close relationships. 2,792). Surveys were administered at six time points: Novem- Examining individual differences in oxytocin and vasopressin ber through December 2001; March through April 2002; function, as manifested by OXTR and AVPR1a variation, con- September through November 2002; March through April stituted an ideal way to do this. We examined three genetic 2003; September through October 2003; and September variants previously shown to predict prosocial behavior: the G through November 2004.1 allele of the OXTR variant rs53576 (e.g., Bakermans-Kranenburg & van IJzendoorn, 2008; Tost et al., 2010), which also predicts DNA collection. At our request, in 2008, Knowledge Networks lower incidence of autism and social anxiety relative to the A recontacted available participants from the life-events study allele (e.g., Wu et al., 2005), and the long forms of the AVPR1a (n = 1,296) and asked them to provide a saliva sample for DNA variants rs1 and rs3 (Knafo et al., 2008). analysis. The majority of participants (54.9%; n = 711) agreed We were interested in whether these genetic variants would to do so; these participants received and returned Oragene predict two types of self-reported prosocial behaviors: engage- (Ottawa, Ontario, Canada) saliva-collection kits (for more ment in volunteer work or charitable activities and commitment information, see http://www.dnagenotek.com) via mail. Kits to civic duty. We also examined whether the polymorphisms were then sent to The Centre for Applied Genomics (Toronto, interacted with perceived threats from the social world in pre- Ontario, Canada; http://www.tcag.ca) for genotyping. dicting these prosocial behaviors. We investigated the following hypotheses: Social and political survey. A subset of the original sample from the life-events study (n = 1,266) completed a Knowledge 1. First, the rs53576 G allele, relative to the A allele, Networks–administered survey on social and political attitudes should (a) predict greater levels of prosocial behav- and involvement between April 2000 and March 2003. Most ior (i.e., engagement in volunteer work or chari- participants (74.8%) completed this survey after August 2002. table activities and commitment to civic duty) and (b) should buffer the connection between perceived threat and prosocial behavior. Measures 2. Second, long forms of the AVPR1a rs1 and rs3 mi- OXTR and AVPR1a polymorphisms. The OXTR variant of crosatellites, relative to short forms, should predict interest, rs53576, consists of a locus at which either the nucleo- greater levels of prosocial behavior. base adenine or the nucleobase guanine (abbreviated “A” and “G,” respectively) can occur. Because every person has one Because of conflicting evidence about the effects of vaso- copy of each gene from each parent, there are three possible pressin on responses to threat, we did not make a prediction genotypes for this OXTR variant: A/A, A/G, or G/G. This about the interactions of the AVPR1a rs1 and rs3 polymor- variant was genotyped using TaqMan SNP-genotyping tech- phisms with threat, but we did explore these interactions. nology (Assays-by-Design Service; Applied Biosystems, Fos- ter City, CA). Samples were analyzed using the ABI 7900HT Sequence Detection System (Applied Biosystems), and geno- Method type calls were made using Sequence Detection System soft- Participants and procedure ware Version 2.1 (Applied Biosystems). Table 1 shows the distribution of OXTR genotypes